Ryan Zimmerman‘s shoulder injury showed no improvement after a round of batting practice yesterday, so the Nationals third baseman will be examined by a specialist in Los Angeles.

Adam Kilgore of the Washington Postreports that Zimmerman is expected to get a cortisone shot, which typically knocks players out of action for at least 2-3 days, and a disabled list stint seems all but certain at this point.

Zimmerman has already been on the active roster without being available to play for nearly a week, so continuing to play short-handed makes little sense for the Nationals even though manager Davey Johnson stressed that they’re willing to wait because “he’s our best player.”

Zimmerman initially hurt his shoulder making several diving plays last week and told Kilgore that he’d likely “get a shot and play” through the injury if it was September rather than April. Doing that for 4-5 months isn’t really an option and after missing most of last season with an abdominal injury Zimmerman stressed that taking a long-term view of the situation is his priority.